build: Replace SCons.Error with exit message
build: Replace SCons.Error with exit message

The build would crash if JAVA_HOME was not specified
because SCons.Error was not imported into the script.
This replaces the error with an exit message.

Change-Id: Ic950ae3dc0d0c3308d7bbd90ab965b17f4563f0f
Signed-off-by: George Nash <acbdc39d528a4315fe0b532d55c50ae46f5c1667@intel.com>
Bug: https://jira.iotivity.org/browse/IOT-1745
Reviewed-on: https://gerrit.iotivity.org/gerrit/20947
Reviewed-by: Phil Coval <ff46fec9739d31cce915aabcc3a7a2c00eee4d6c@osg.samsung.com>
Tested-by: jenkins-iotivity <d95b56ce41a2e1ac4cecdd398defd7414407cc08@iotivity.org>

iotivity/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,iotivity/iotivity